Inflatable vehicle occupant restraint devices, generally known as "air bags," have proved to be a life saving product. Since the inflator used in such inflatable occupant restraint systems is one of the heaviest and most expensive components of the air bag system, there is a need for a lighter, less expensive inflator.
Conventional air bag inflators are relatively thick walled due to the fact that wall thickness must be sized to contain the maximum gas pressure exhibited under the most adverse condition. Such inflators incorporate apertures for the discharge of gas produced by combustion of a propellant that are sealed from the ambient environment by discrete seals.
A typical inflator comprises a cylindrical perforated steel housing of a diameter and length related to the application. Typically, one or more layers of steel screen of varying mesh and wire diameter are disposed about an internally disposed propellant. Gases produced in the combustion process pass through the screen, then rupture the seals.